Alkoxylated quaternary ammonium salts of esters of salicylic acid as microbicides



United States Patent ALKOXYLATED QUATERNARY AMMONIUM SALTS OF ESTERS OF SALICYLIC ACID AS MICROBICIDES Elizabeth L. Fareri, Pittsburgh, Robert J. McGuire, Monroeville, and Edward Mitchell, Valencia, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Filed Aug. 2, 1965, Ser. No. 476,666

8 Claims. (Cl. 44-63) ABSTRACT OF THE DISCLOSURE Alkoxylated quaternary ammonium salts of esters of salicylic acid are used as microbicides in hydrocarbon oil.

this invention can be selected from compounds having the general structure wherein:

R is a normal or iso alkyl, normal or iso alkenyl, aralkyl or cycloalkyl substituent containing 1 to 22 carbon atoms and can be substituted with substituents such as nitrogen, halogen, phosphorus, sulfur or oxygen,

R may be absent or is a normal or iso alkyl, a normal or iso alkenyl, aralkyl, or cycloalkyl substituent containing 1 to 22 carbon atoms and can be substituted with substituents such as nitrogen, halogen, phosphorus, sulfur or oxygen,

where x=0 to 2, and y+z=2 to 15,

R, and R are each a normal or iso alkyl, a normal or iso alkenyl, aralkyl, or cycloalkyl substituent containing 1 to 22 carbon atoms which can be substituted with substituents such as nitrogen, halogen, phosphorus, sulfur or oxygen, at least one of said substituents containing at least 4 carbon atoms,

N is nitrogen and can be the nitrogen member of a heterocyclic nitrogen-containing ring such as imidazoline,

pyridine, thiazine or piperazine, in which case R and R are part of the heterocyclic ring, C is carbon, and O is oxygen.

Preferred compounds include NH (CH2OH2O)yH COOR where R is a C to C -alkyl substituent such as oleyl;

R can be octyl, isooctyl, dodecyl, tridecyl or hexadecyl;

and x+y=2.

Salicylic acid is a convenient starting material in the preparation of the alkoxylated quaternary ammonium salicylates of this invention. Salicylic acid contains an hydroxyl radical and a carboxylic acid radical at ortho positions on a benzene ring. In preparing the quaternary ammonium salts of this invention, the reactant containing the quaternary ammonium cation is reacted with the hydroxyl radical of the salicylic acid rather than with the carboxylic radical so that the salt formed is a quaternary ammonium phenate rather than a quaternary ammonium carboxylate. However, the carboxylic acid radical is considerably more acidic and therefore more reactive with the quaternary ammonium cation than is the hydroxyl radical and in order for the quaternary ammonium cation to react with the hydroxyl radical rather than with the carboxylic acid radical the salicylic acid must be esterified prior to the reaction thereof With the quaternary ammonium compound. Therefore, the preparation of the quaternary ammonium salt of this invention is a two-step process in which the order of performance of the steps is critical, i.e., the salicylic acid starting material is first esterified by reaction with an alcohol and only after esterification is it converted to a quaternary salt by reaction with a compound such as a quaternary ammonium hydroxide. Following is a specific example of a two-step process for the preparation of a quaternary ammonium salt of an ester of salicylic acid.

EXAMPLE 1 Step 1.Preparation of isooctyl salicylate from salicylic acid A mixture containing 900 grams of salicylic acid, 1300 grams (10 moles) of isooctyl alcohol, 30 grams of ptoluenesulfonic acid and 1000 milliliters of toluene was heated at reflux in a 5-liter flask fitted with a Dean and Stark trap. Reflux was continued until no more water collected in the trap. The solution was cooled to room temperature and extracted with one liter of water, then with one liter of 10 percent sodium bicarbonate solution followed by a washing with one liter of water. The extracted solution was dried over anhydrous sodium sulfate, filtered and vacuum distilled. After distillation of toluene and excess isooctyl alcohol, 1568 grams of a clear oil was collected at -160 C. and 3.2 millimeters pressure. Analysis of the product showed 72.21 percent carbon, 8.90 percent hydrogen, 18.21 percent oxygen and a molecular weight of 265. Theoretically, isooctyl salicylate contains 71.9 percent carbon, 8.8 percent hydrogen, and 19.2 percent oxygen, and has a molecular weight of 250.

Step 2.-Preparation of dihydroxyethylmethyloleylammonium isooctyl salicylate from isooctyl salicylate To 12.5 grams (0.05 mole) of isooctyl salicylate in 30 milliliters of benzene was added 29.3 grams (0.05 mole based on neutralization equivalent) of dihydroxyethylmethyloleylammonium hydroxide in isopropanol solution. The mixture was stirred. Solvents, including water of reaction, were removed at reduced pressure with slight heating. The product, dihydroxyethylmethyloleylammonium isooctyl salicylate, a viscous clear brown liquid, weighed 29.1 grams and had a nitrogen content of 2.17 percent by weight. The theoretical nitrogen content of dihydroxyethylmethyloleylammonium isooctyl salicylate is 2.3 percent by weight.

Tests were conducted to illustrate the high microbicidal activity in hydrocarbon oil of compounds of this invention and to show the unusual superiority in microbicidal activity in hydrocarbon oil of the alkoxylated quaternary ammonium salicylates of the invention as compared to similar compounds wherein the hydroxyalkyl substituents of the quaternary ammonium group are replaced by hydroxyl-free alkyl groups or as compared to compounds wherein the entire quaternary ammonium group is replaced by a metal. In each of the tests, 50 milliliters of mycophil broth was sterilized in an autoclave for 15 minutes at 250 F. Thereupon, 300 milliliters of fuel oil, or fuel oil plus additive, was added. The oil-broth mixture was inoculated with a mixed culture of microorganisms from the water bottoms of a domestic fuel oil storage tank. The domestic fuel oil from which the microorganisms were obtained was an oil similar to that employed in the oilbroth mixture. The flask was stoppered with a cotton plug and stored at room temperature in the dark. The samples were examined once each week for 60 days, and the amount of bacterial growth was rated. In the ratings, designates no growth; designates slight growth; 2+ designates fair growth; 3+ designates good growth; and 4+ designates excellent growth. At a rating of 4+, or in 60 days, each test was terminated. The

result of each test is shown in the following table.

Sample: Microbial growth rating Control fuel oil 4+ in 11 days Control fuel oil plus 0.02 percent by weight of dihydroxyethylmethyloleylammonium isooctyl salicylate 0 in 60 days Control fuel oil plus 0.01 percent by weight of dihydroxyethylmethyloleylammoniumisooctylsalicylate 0 in 60 days Control fuel oil plus 0.02 percent by 3+ in 60 days 4+ in days phenate 4+ in 21 days 1 Typical fuel oil inspections:

Gravity: API, ASTM D287 30.1

Viscosity SUV: Sec., ASTM D446 100 F 33 .9

Flash, P-M: F., ASTM D93 Pour: F., ASTM D97 Carbon residue. D524 on Distillation, ASTM D158 Over point F 372 End point F 620 At 432 F. percent 10 At 488 F. do 5 At 573 F. (lo 1.1 Residue d0 1.1

The above data clearly show that the alkoxylated quaternary ammonium salicylates of this invention have a high microbicidal activity when present in small concentrations in hydrocarbon oil and are remarkably superior in microbicidal activity as compared to similar compounds in which the hydroxyalkyl substituents of the quaternary ammonium group are replaced by hydroxylfree alkyly substituents or related compounds in which the quaternary ammonium group is replaced by a metal.

The alkoxylated quaternary ammonium salicylates of this invention are oil soluble and can be present in hydrocarbon oils over a wide range of concentrations. For example, they can be generally present in hydrocarbon oils over a concentration range of about 0.002 to about 10 percent by weight, the higher region of the range being especially useful when preparing a concentrate, or, preferably, over a concentration range of about 0.005 to about 2 percent by weight. Although useful in a wide variety of hydrocarbon oils such as gasoline, jet fuels, diesel fuels, etc., the alkoxylated quaternary ammonium salicylates of this invention are especially useful in fuel oils, including blends of straight run and catalytically cracked fuel oils. Fuel oils containing the compounds of this invention are commonly in contact with a water phase.

Various changes can be made without departing from the spirit of this invention or the scope thereof as defined in the following claims.

We claim:

1. A composition comprising a hydrocarbon oil in contact with a water phase having dissolved in said oil an oil soluible hydroxylated quaternary ammonium salt of an ester of salicylic acid, said salt being a quaternary ammonium phenate with the ester portion thereof formed from an alcohol containing 1 to 22 carbon atoms.

2. The composition of claim 1 wherein there is attached to the ring structure of said salicylic acid an alkyl, alkenyl, aralkyl or cycloalkyl substituent containing 1 to 22 carbon atoms.

3. The composition of claim 1 wherein attached to the quaternary nitrogen atom are the su'bstituents H 11 J o H 1'1 It and H H J: 0 H 11 1 1 X z where x=0 to 2, and y+z:2 to 15.

4. The composition of claim 1 wherein also attached to the quaternary nitrogen atom are alkyl, alkenyl, aralkyl or cycloalkyl substituents containing 1 to 22 carbon atoms, one of which contains at least 4 carbon atoms.

5. The composition of claim 1 wherein said hydrocarbon oil is fuel oil.

6. The composition of claim 1 wherein the concentration of said oil soluble salt in said hydrocarbon oil is between about 0.002 and 10 percent by weight.

7. A composition comprising hydrocarbon oil in contact with a water phase containing an oil solu ble compound having the structure wherein R is a su'bstituent containing 1 to 22 carbon atoms,

Ra R

R,,N+Rb

wherein R is a substituent containing 1 to 22 carbon atoms,

R, is

R IS

where :0 to 2, and y+z=2 to 15, and R and R are members of the same heterocyclic ring.

References Cited UNITED STATES PATENTS 9/1942 Shelton 167-30 12/1943 Buck et a1. 16730 1/1945 Shelton 167-30 11/1945 Kirby et a1. 167-30 3/ 1946 Bock et al 16730 4/1958 Erskine 252-392 5/1954 Gash et a1. 260243 3/ 1961 Summers 4478 US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,419,366 December 31,

Elizabeth L. Fareri et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, lines 5 to 9, the left-hand portion of the formula should appear as shown below:

RaN

Column 4, lines 28 to 39, the formula should appear as shown below:

H H H H H H I I I I I I l: (2X I and T T 012 H H H H H H Column 5, lines 8 to 16, the formula should appear as shown below:

b c a d Signed and sealed this 17th day of March 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J

Attesting Officer Commissioner of Patent 

